Method and device for managing information exchange between a main element, for example a nfc controller, and a set of at least two auxiliary elements

ABSTRACT

A device, including a main element (ME) and a set of at least two auxiliary elements (SEi), said main element including a master SWP interface (MINT), each auxiliary element including a slave SWP interface (SLINTi) connected to said master SWP interface of said NFC element through a controllably switchable SWP link (LK) and management means (PRMprocessor, CTLM, AMGi) configured to control said SWP link switching for selectively activating at once only one slave SWP interface on said SWP link.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/994,607, filed May 31, 2018, which application is acontinuation of U.S. patent application Ser. No. 15/335,636, filed Oct.27, 2016, now U.S. Pat. No. 10,244,372, which application is acontinuation of U.S. patent application Ser. No. 13/994,283, filed Sep.6, 2013, now U.S. Pat. No. 9,515,701, which application is a NationalStage entry of PCT Application No. PCT/EP2011/072474, filed on Dec. 12,2011, which application claims priority to EP Patent Application Nos.11305359.9, filed Mar. 30, 2011 and 10306416.8, filed Dec. 15, 2010,which applications are hereby incorporated by reference herein in theirentirety.

TECHNICAL FIELD

The invention relates to the communication between components orelements, in particular between a contactless element, for example, anNFC (“Near Field Communication”) controller element and at least twoauxiliary elements, such as a UICC or secure elements, for example,located within a wireless apparatus, for example, a mobile phone.

BACKGROUND

As defined within ETSI TR 102 216 V3.0.0 (2003 September), UICC, whichis neither an abbreviation nor an acronym, designates a smart card thatconforms to the specifications written and maintained by the ETSI SmartCard Platform project.

Further to its conventional telephone function, a mobile phone may beused for exchanging information with a contactless device by using acontactless communication protocol.

This permits to exchange information between the contactless device andelements located within the mobile phone. Plenty of applications arethus possible such as mobile ticketing in public transport (the mobilephone acts as a boarding pass) or mobile payment (the mobile phone actsas a debit/credit payment card).

Near Field Communication or NFC is a short-range high-frequency wirelesscommunication technology that enables such exchange of data between twocontactless devices over a short distance, for example, 10 centimeters.

NFC is an open platform technology standardized in ISO/IEC 18092 andISO/IEC 21481 but incorporates a variety of pre-existing standards,including ISO/IEC 14443 protocol type A and type B.

Mobile phone manufacturers are interested in connecting two differentauxiliary elements to NFC chips. As a matter of fact, having twoseparate auxiliary elements allows two clearly separate applicationscoming from different issuers (banks, transport operators, telephoneoperators, . . . ).

ETSI TS 102 613 is a standard disclosing, in particular, the principleof a so-called Single Wire Protocol (SWP). The SWP is a bit-orientedpoint-to-point communication protocol between a contactless front end(CLF) also called an NFC controller, and a UICC. However, this singlewire protocol as defined in ETSI TS 102 613 permits only thecommunication between one contactless element, for example, one NFCcontroller and one UICC.

A first solution for managing information exchange between an NFCcontroller and two elements consists in providing an NFC controller withone SWP interface for secure elements based on SWP-UICC technology and asecond interface (for example, an NFC Wired Interface: NFC-WI) forproprietary secure elements. However, such a solution makes the designof an NFC controller more complex as an additional interface has to bemanaged in a time-critical environment.

A second solution consists in offering NFC controllers provided with twoSWP interfaces. This solution would allow using of two secure elementsprovided with SWP-UICC technology, but again, it will make the design ofthe NFC controller more complex as an additional interface has to bemanaged.

SUMMARY

According to an embodiment, a method and a device are proposed formanaging in a simple way, information exchange between a contactlesselement such as NFC controller, and several (at least two) auxiliaryelements by using the already existing hardware technology without anymodification of the software on secure elements provided with SWP-UTCCtechnology.

According to an aspect, a method of managing information exchangebetween a main element, in particular, a contactless element, forexample, a NFC element such as a NFC controller, and a set of at leasttwo auxiliary elements is provided which comprises providing eachauxiliary element with a slave SWP interface, providing said mainelement with a master SWP interface, connecting said slave SWPinterfaces to said master SWP interface through a controllablyswitchable SWP link and controlling said SWP link switching forselectively activating at once only one slave SWP interface on said SWPlink.

A slave SWP interface is considered to be activated when for example, itis capable, after an activation phase including the transmission ofparticular control data, to exchange information with the masterinterface on the SWP link related for example to a particularcontactless application.

According to an embodiment, connecting said slave SWP interfaces to saidmaster SWP interface through a controllably switchable SWP linkcomprises connecting a controllable multiplexer/demultiplexer switchbetween said master SWP interface and said slave SWP interfaces andcontrolling said SWP link switching comprises controlling saidmultiplexer/demultiplexer switch for switching the SWP link to saidselected slave SWP interface.

According to an embodiment, said method further comprises forcing thepart of the SWP link connected between each non-selected slave SWPinterface and the multiplexer/demultiplexer switch in a deactivatedstate.

This permits for the non-selected slave SWP interface, to simulate thepresence of the master element even if this master element is actuallyexchanging information with the selected slave interface.

Further, as the parts of the SWP link connected between each selectedslave SWP interface and the multiplexer/demultiplexer switch are forcedin a deactivated state, there is no risk that one of said non-selectedslave SWP interface detects a non-working SWP link, while the selectedslave SWP interface is active.

As a matter of fact, an auxiliary element cannot initiate SWPcommunication while SWP link is deactivated.

According to an embodiment, said method further comprises controllingsaid SWP link switching when the SWP link is in a deactivated state.

In other words, it is only possible to switch the SWP link to anotherauxiliary element when the SWP is deactivated. Thus, all auxiliaryelements assume a deactivated SWP link, and all auxiliary elements willnot recognize any change on SWP link when SWP switching happens.

Activating said selected slave SWP interface may comprise performing aninitial activation of said selected slave SWP interface or subsequentactivation of said selected slave SWP interface.

According to an embodiment, either all the auxiliary elements operate ina first operation mode, for example in a full power mode, or only oneauxiliary element operates in a second operation mode, for example in alow power mode, having a power value lower than the power value of thefirst operation mode, while each other auxiliary element is OFF, andwhen said only one auxiliary element operates in a second operationmode, controlling said SWP link comprises forcing the SWP link switchinginto a predetermined configuration allowing the selection of said onlyone auxiliary element.

This permits to surely have a switching of the SWP link to said only oneauxiliary element, even if the multiplexer/demultiplexer switch is notsufficiently powered.

According to another embodiment, either all the auxiliary elementsoperate in the first operation mode, or at least a first auxiliaryelement operates in the second operation mode, and when said firstauxiliary element operates in a second operation mode, said firstauxiliary element controls said SWP link switching for selecting onlyone auxiliary element operating in a second operation mode.

It is thus possible to have a more flexible configuration in the lowpower mode.

More particularly, a configuration indication may be stored in saidfirst auxiliary element, and said first auxiliary element controls saidSWP link switching by using said configuration indication.

While it is possible to store the configuration indication during thefabrication of the device, thus fixing a configuration by default forthe low operation mode, it is particularly advantageous that forexample, the user of a wireless apparatus may decide himself theconfiguration in the low power mode.

And in this respect, said configuration indication may be stored in saidfirst auxiliary element when all the auxiliary elements operate in saidfirst operation mode, for example, through a user interface.

According to an embodiment said first auxiliary element operates in asecond operation mode, said first auxiliary element controls thepowering of each other auxiliary element in order to place each otherauxiliary element in an OFF state and said first auxiliary elementcontrols said SWP switching for selecting said first auxiliary elementoperating in a second operation mode.

According to another embodiment said first auxiliary element operates ina second operation mode, said first auxiliary element controls thepowering of a second auxiliary element in order to permit said secondauxiliary element to operate in a second operation mode and said firstauxiliary element controls the SWP link switching for selecting saidsecond element operating in a second operation mode.

Said first auxiliary element may control the powering of said secondauxiliary element or each other auxiliary element by using saidconfiguration indication.

According to another aspect, a device is proposed, comprising a mainelement and a set of at least two auxiliary elements, said main elementincluding a master SWP interface, each auxiliary element including aslave SWP interface connected to said master SWP interface of said NFCelement through a controllably switchable SWP link and management meansconfigured to control said SWP link switching for selectively activatingat once only one slave SWP interface on said SWP link.

According to an embodiment, the device comprises a controllablemultiplexer/demultiplexer switch having a first terminal coupled to saidmaster SWP interface through a first part of said SWP link and at leasttwo second terminals respectively coupled to said at least two slave SWPinterfaces through at least two second parts of said SWP link, and saidmanagement means comprise control means configured to control saidmultiplexer/demultiplexer switch.

Said control means may be advantageously located within said mainelement.

According to an embodiment, the device further comprises first forcingmeans configured to force each second part of the SWP link connectedbetween each non selected slave SWP interface and themultiplexer/demultiplexer switch in a deactivated state.

According to an embodiment, said first forcing means comprise at leasttwo pull-down resistors respectively connected between said at least twosecond parts of said SWP link and a reference voltage.

According to an embodiment, said management means comprise processingmeans configured to put said SWP link in a deactivated state, and saidcontrol means are configured to control said multiplexer/demultiplexerswitch after said processing means have put the SWP link in saiddeactivated state.

Said management means may be configured to perform either an initialactivation or subsequent activation of said selected SWP slaveinterface.

According to an embodiment, the device has

a first state in which all the auxiliary elements are able to operate ina first operation mode, for example in a full power mode, and

a second state in which only one auxiliary element is able to operate ina second operation mode, for example in a low power mode, having a powervalue lower than the power value of the first operation mode, and eachother auxiliary element is OFF, and

said device further comprises second forcing means configured, when saidlink switching into further comprises second forcing means device is inits second state, to force the SWP a predetermined configurationallowing the selection of said only one auxiliary element.

According to an embodiment, said second forcing means comprise anotherpull-down resistor connected between the control input of saidmultiplexer/demultiplexer switch and a voltage reference.

According to a variant the device has a first state in which all theauxiliary elements are able to operate in the first operation mode, anda second state in which at least a first auxiliary element is able tooperate in the second operation mode and said device comprises auxiliaryselection means at least partly incorporated in said first auxiliaryelement and configured, when said device is in its second state, tocontrol said SWP link switching for selecting only one auxiliary elementoperating in a second operation mode.

According to an embodiment said auxiliary selection means comprisesauxiliary memory means incorporated in said first auxiliary element forstoring a configuration indication, and auxiliary control meansconfigured to control the SWP link switching from said configurationindication.

Said auxiliary selection means may further comprise auxiliary inputmeans configured to store said configuration indication is stored insaid auxiliary memory means when the device is in its first state.

Said auxiliary selection means may be further configured, when saiddevice is in its second state, to control the powering of each otherauxiliary element in order to place each other auxiliary element in anOFF state, and to select said first auxiliary element operating in asecond operation mode.

Said auxiliary selection means may be also configured, when said deviceis in its second state, to control the powering of a second auxiliaryelement in order to permit said second auxiliary element to operate in asecond operation mode, and to select said second element operating in asecond operation mode.

According to an embodiment said auxiliary selection means comprisesauxiliary power control means configured to control the powering of saidsecond auxiliary element or each other auxiliary element from saidconfiguration indication.

According to an embodiment, one auxiliary element may be packed withsaid main element and another auxiliary element, for example a SIM card,may be removably connected to said main element.

Said main element may be a contactless element, for example a NFCcontroller.

According to another aspect, an apparatus, for example a wirelesscommunication apparatus, is proposed comprising an antenna and a deviceas defined above, coupled to said antenna.

According to an embodiment, one auxiliary element may be permanentlyfixed within said apparatus and another auxiliary element, for example aSIM card, may be removably lodged within said apparatus and removablyconnected to said main element.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and features of the invention will appear on examiningthe detailed description of embodiments, these being no way limiting,and of the appended drawings in which:

FIG. 1 illustrates schematically an embodiment of a device according tothe invention;

FIGS. 2 and 3 illustrate connections between a main element andauxiliary elements through a SWP link;

FIGS. 4, 5 a, 5 b illustrate diagrammatically examples of flow charts ofseveral embodiments of a method according to the invention;

FIGS. 6-9 illustrate diagrammatically examples of frames used inembodiments of the present invention;

FIGS. 10 and 11 illustrate diagrammatically other examples of flowcharts related to initial and subsequent activations;

FIG. 12 illustrates diagrammatically an embodiment of amultiplexer-demultiplexer switch in the present invention;

FIGS. 13 and 14 illustrate diagrammatically embodiments of a wirelessapparatus according to the invention; and

FIGS. 15 to 18 illustrate diagrammatically other embodiments of a methodand a wireless apparatus according to the invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Embodiments of the invention will be now described in the technicalfield of contactless elements or components connected to secureelements, in particular, embedded in a mobile phone, although theinvention is not limited to these particulars embodiments.

A contactless element is an element or a component able to exchangeinformation through an antenna with a contactless device according tocontactless communication protocol.

An NFC element or component, which is a contactless element, is anelement or component compliant with the NFC technology.

In FIG. 1, an example of a device DIS according to the invention isillustrated, which comprises a contactless front end element ME, forexample an NFC controller, having a SWP interface MINT.

The device also comprises here two auxiliary elements or secureelements. Each secure element SEI (SE2) comprises a SWP interface SLINT1 (SLINT 2). Each SWP interface SLINTi is connected to the same SWPinterface MINT of the NFC controller ME through a controllablyswitchable SWP link LK.

A secure element is, for example, an element adapted to contain secureor protected information, for example banking information, informationrelated to telephone subscription, among others.

Each SWP interface SLINTi comprises auxiliary management means AMGiwhile the SWP interface MINT of the NFC controller ME comprisesprocessing means PRM.

The NFC controller ME is coupled to an antenna ANTI for exchanginginformation with a contactless reader by using a contactlesscommunication protocol, for example, the one disclosed in ISO/IEC 14443.

The Single Wire Protocol (SWP) is a bit oriented, point-to-pointcommunication protocol between a secure element and a contactless frontend, and is specified in the standard ETSI TS 102 613, for example, theversion V7.7.0 (2009 October) thereof. The man skilled in the art couldrefer if necessary to this document, the content thereof beingincorporated by reference in the present patent application.

More precisely, as illustrated in FIG. 2, the NFC controller ME is themaster, whereas a secure element SE is a slave. The master and a slaveare mutually connected through an SWP link LK.

An SWP link is a link or line adapted to support the Single WireProtocol (SWP).

As disclosed in ETSI TS 102 613, the principle of the single wireprotocol (SWP) is based on the transmission of digital information infull-duplex mode. The signal S1 from ME to SE is transmitted by adigital modulation (L or H) in the voltage domain whereas the signal S2from SE to ME is transmitted by a digital modulation (L or H) in thecurrent domain.

When the master sends S1 as state H then the slave may either draw acurrent (state H) or not (state L) and thus transmits S2. With pulsewidth modulation bit coding of S1, it is possible to transmit atransmission clock, as well as data in full-duplex mode. More detailscan be found in ETSI TS 102 613.

FIG. 3 represents an embodiment of the physical link between thecontactless element ME and a secure element SE. More precisely, asillustrated in this figure and explained in ETSI TS 102 613, the contactC6 of the secure element is connected to the port SWIO of thecontactless element ME for transmission of signal S1 and S2.

The SWP protocol specified in ETSI TS 102 613 permits only thecommunication between the master SWP interface of the contactlesselement and a single slave SWP interface of a single secure element.

According to an aspect of the invention which will be now described morein details, it will be possible to connect two or more than twoauxiliary elements or secure elements SEi provided with an SWP-UICCtechnology to a single master SWP interface of a contactless element,for example, an NFC controller.

More precisely, if we refer again to FIG. 1, this will be possible inparticular by connecting a controllable multiplexer/demultiplexer switchSW between said master SWP interface MINT and said slave SWP interfacesSLINT1, SLINT2, and by controlling said switch SW by control means CTLMfor switching the SWP link to the selected slave SWP interface.

Here, the processing means PRM, the control means CTLM, and theauxiliary management means AMGi form management means configured tocontrol the SWP link switching for selectively activating at once onlyone selected slave SWP interface on said SWP link.

The management means and the control means may be realized by softwaremodule and at least partly by logic circuit.

In the present embodiment, where only two auxiliary elements are used,the multiplexer/demultiplexer switch SW has a first terminal T1 coupledto said master SWP interface MINT though a first part LK1 of said SWPlink LK and two second terminals T20 and T2 respectively coupled to saidtwo slave SWP interfaces SLINT1, SLINT2 through two second parts LK20,LK21 of said SWP link.

Of course, although the parts LK1, LK20, and LK21 have been representedhere by wires between the terminals T1, T20, T21 and the correspondingterminals of the SWP interfaces, these parts may be reduced to theminimum if for example the terminals T1, T20, T21 respectively meet thecorresponding terminals of the SWP interfaces.

The switch SW further comprises a control terminal T3 connected to thecontrol means CTLM for receiving a control signal SWCTRL for switchingthe first terminal T1 to either the second terminal T20 or the secondterminal T21, depending on the logic value of the control signal.

For example, as illustrated in FIG. 1, if the control signal SWCTRL hasthe logic value “0”, the first terminal T1 is connected to the secondterminal T20 while the first terminal T1 is connected to the secondterminal T21 if the control signal SWCTRL has the logic value “1”.

As defined in ETSI TS 102 613, an SWP link may have an activated state,a suspended state and a deactivated state.

More precisely, in the activated state, the master element and theselected auxiliary element are sending bits.

In the suspended state, the signal S1 is in state H and the signal S2 isin state L.

In the deactivated state, the signal S1 is in state L and the signal S2is in state L.

As it will be explained more in detail, controlling the switch SW isonly performed when the SWP link LK is in its deactivated state.

Further, when a secure element SE 1, for example, has been selected, thepart of the SWP link seen by the other non-selected secure element (SE2for example), is advantageously in a deactivated state.

Placing such part of the SWP link in a deactivated state is equivalentto place the C6 contact of said corresponding non-selected secureelement in a low state, typically at ground.

Resistors R20 and R21 respectively connected between the second terminalT20 and a voltage reference, for example, ground, and between secondterminal T21 and the voltage reference, are pull-down resistors. And,the pull-down resistor R20 permits to force the part LK20 of the SWPlink in a deactivated state when the secure element SE2 has beenselected while pull-down resistor R21 forces the part LK21 of the SWPlink in its deactivated state when the secure element SE1 has beenselected.

Further, another pull-down resistor R3 connected between the controlinput T3 and the voltage reference (ground, for example) permits toforce the control input to the logical value “0” thereby forcing theswitch in the predetermined configuration in which terminal T1 isconnected to terminal T20, in the case the switch SWP is notsufficiently or not at all powered.

The value of each pull-down resistor is chosen to have, for example, acurrent having a very small value, for example 5 μA or 10 μA.

We refer now more particularly to FIG. 4, which illustrates a particularembodiment of a method according to the invention.

After the master element boot, the processing means PRM of the masterelement put the SWP link in its deactivated state (step 400) in order toselect (step 401) one secure element, for example, secure element SE1.In this respect, the control signal SWCTRL has the logic value “0”.

Since the secure element SE1 has been selected, the part LK21 of the SWPlink seen by the other non-selected secure element SE2 is forced to bein a deactivated state by the pull-down resistor R21 (the signal S1 ispulled down to state L by the resistor R21).

Of course, as explained above, forcing the part of the SWP link seen bythe non-selected secure element in its deactivated state is equivalentto force the potential of the C6 contact of said secure element to a lowstate (ground, for example).

Once the secure element SE1 has been selected, the management means(processing means and auxiliary management means) perform an initial SWPactivation (step 402) of the corresponding slave SWP interface, asdefined in ETSI TS 102 613.

Activating a slave SWP interface leads to place said slave SWP interfacein an activated state. For example, activating a slave SWP interfacecomprises performing an activation phase during which control data areexchanged between the master interface and the slave interface. At theend of the activation phase, the master and the slave have been mutually“recognized,” and the slave is ready to exchange payload informationrelated to a particular contactless application with the contactlesselement. The slave interface is thus activated (or in an activatedstate).

Once the initial SWP activation sequence is finished, the processingmeans of the main element ME put the SWP link into its suspended state,and wait for communication from the activated slave interface of thesecure element.

If the conditions are fulfilled to deactivate the secure element, theprocessing means of the main element put the SWP link in its deactivatedstate (step 404). Such conditions are for example, those detailed inpoint 8.3 of ETSI TS 102 613.

Now, the main element ME is able to switch the SWP link between thesecure element SE1 and the secure element SE2 (step 406).

In this respect, the switch control SWCTRL takes the logic value “1”.

An initial SW activation (step 402) is performed for the secure elementSE2, while the part LK20 of the SWP link seen by the non-selected secureelement SE1 is forced in its deactivated state by the pull-down resistorR20 (step 407).

For example, an event that can lead to an initial SWP activation ofsecure element SE2, which is, for example, a UICC, is the reception of asignal from the main processor.

Once the initial SWP activation sequence is finished for the secureelement SE2, the processing means of the main element ME put the SWPlink into its suspended state to wait for SWP communication from secureelement SE2. If no activity is required on this interface, theprocessing means of the main element put the SWP link in its deactivatedstate (step 404).

If another secure element SE is to be activated, thus a new selection isperformed followed by initial activation of this new selected secureelement (step 402).

If no other secure element is to be activated (step 405), the SWP linkremains in its deactivated state.

At this stage, if an SWP communication with a secure element SEi isrequired (step 501) (upon, for example, reception of an external eventcoming from the application supported by this secure element), thissecure element SEi is selected (step 502).

Of course, if the switch SWP is already in the configuration forselecting this secure element, no change is performed on the switch.

Then, a subsequent activation (step 504), as defined in ETSI TS 102 613,is performed for this secure element SEi, while the part of SWP linkseen by each non-selected secure element SEj (contact C6 of eachnon-selected secure element SEj) is in its deactivated state (step 503).

Once the selected slave interface SLINTi of the secure element SEi hasbeen activated (step 505), a SWP communication between the main elementME and this secure element SEi may be performed (step 506) until theconditions are fulfilled allowing to deactivate the SWP link as forexample described within chapter 8.3 of ETST TS 102 613, for example,until the reception of a signal named EVT_HCI_END_OF_OPERATION in ETSITS 102 622 (step 507).

Such signal indicates the end of communication with the secure elementSEi.

After the conditions are fulfilled, the SWP link is put again in itsdeactivated state (step 508) by the processing means PRM of the mainelement SE.

If a new SW communication is required with the previously selectedsecure element SEi, thus, the control signal SWCTRL is not modified(step 510) and a subsequent activation (step 511) is performed foractivating the slave interface SLINTi of this secure element SEi (step512) permitting thus the SWP communication with this secure element(Step 513).

If an SWP communication is required with a secure element SEj, differentfrom the previously selected secure element SEi, then, this new secureelement SEj is selected (step 514) by modifying the value of the controlsignal SWCTRL.

A subsequent activation (step 516) is performed for this new selectedsecure element SEj, while maintaining the contact C6 of each othernon-selected secure element in a low state (step 515).

Once the slave interface SLINTj of this secure element SEj has beenactivated (step 517), an SWP communication between the main element MEand the secure element SEj may be performed (step 518).

An initial activation and subsequent activation of a slave interface aredisclosed in ETSI TS 102 613.

The man skilled in the art may refer to this standard if necessary.

Some details about these activations are now briefly described withreference to FIGS. 6-11.

According to ETSI TS 102 613, particular control frames, called ACTframes, are exchanged between the NFC controller ME and a secure elementSE during an activation phase.

Such an ACT frame, referenced CPR, is diagrammatically illustrated inFIG. 6.

More precisely, the first three bits of byte 1 of the frame CPR declarethe SWP frame as an ACT frame. The FR bit indicates an eventuallycorrupted previously received ACT frame (only used by the NCF controllerME). The INF bit indicates that the last payload byte contains the ACTINFORMATION field and the ACT CTRL bits b1 b2 b3 define the meaning ofthe ACT frame. After byte 1, 0-3 payload bytes follow, the contentthereof depending of the content of ACT_CTRL and FR fields.

More precisely, when the bits b1 b2 b3 have respectively the binaryvalues 000, the corresponding frame CFR1 is a so-called ACT_READY frameindicating that the secure element has been activated and is ready forexchanging information with the contactless element (FIG. 7).

When the bits b1, b2, b3 have respectively the binary values 001, thecorresponding frame CFR2 is a so-called ACT_SYNC frame sent by a secureelement and containing the identification SYNC_ID of this secure element(FIG. 8).

When the bits b1 b2 b3 have respectively the binary values 010, thecorresponding frame CFR3 (FIG. 9) is a so-called ACT POWER MODE framesent by the contactless element and indicating the power mode (fullpower or low power).

FIG. 10 is more particularly directed to an initial activation of aslave interface. An initial activation is performed in particular afterthe first powering up of the device or after a new powering up followinga power interruption.

First, the SWTO signal (see FIGS. 2 and 3) which is in its low state Lis set to its high state H by the NFC controller (state 80). The SWPlink is in its suspended state.

In ETSI TS 102 613 a secure element that detects such state H on itscontact C6 has a predetermined duration (700 μs) for resuming the SWPlink.

The auxiliary management means of the slave interface of the secureelement SE, which is the selected secure element, sends, after havingresumed the SWP link, an ACT_SYNC frame CFR2 (step 83).

Then, the activation process continues depending on the power mode (step85).

More precisely, the NFC controller ME sends an ACT_POWER_MODE frame CFR3(step 86) in the case of a full power mode.

Upon receipt of this frame CFR3, the auxiliary management means of theselected secure element SE send an ACT READY frame CFR1 (step 87).

The SWP interface of the secure element SEn is thus considered as beingactivated.

If the power mode is a low power mode, the interface of the selectedsecure element SE is considered as being activated after step 83.

FIG. 11 illustrates diagrammatically a subsequent activation of secureelement SE.

In step 91, the auxiliary management means of the secure element SE sendon the link LK the ACT_SYNC frame.

The slave SWP interface of the secure element SE is thus considered tobe subsequently activated.

FIG. 12 illustrates diagrammatically an embodiment of an analogmultiplexer/demultiplexer switch SW allowing connection with two secureelements.

In this embodiment, the switch SW is a passive switch. It comprises, forexample, two NMOS transistors TRA and TRB. The input control T3 of theswitch SW is connected to the gate of transistor TRA and to the gate oftransistor TRB through an invertor INV.

The terminal T20 of the switch SW is connected to one electrode (thedrain, for example) of the transistor TRA, while the terminal T21 of theswitch SW is connected to the electrode (the drain, for example) oftransistor TRB.

The other electrode (the source, for example) of each transistor TRA andTRB are both connected to the terminal Tl of the switch SW.

It is also possible to use an active multiplexer/demultiplexer switch asfor example, the one available at the company STMicroelectronics underthe reference STG5123.

Such an active multiplexer/demultiplexer switch which is a high-speedCMOS low voltage single analog SPDT (Single-Pole Double Throw) switch or2:1 multiplexer/demultiplexer switch, has a lower resistivity and alower input capacity.

As illustrated in FIG. 13 and FIG. 14, the device DIS may beincorporated in a wireless apparatus WP such as a mobile phone. Moreprecisely, the mobile phone comprises here conventionally a mainprocessor (application or baseband processor) exchanging informationwith the secure element SE1, for example, a UICC, of the device throughsignal CLK, RST, I/O compliant with ETSI TS 102 221 permitting thus thetelephone functionality through the antenna ANT2.

The NFC controller ME is connected to the main processor through anotherbus, for example, an I²C bus.

The secure element SE2 is for example, used for banking operations.

The secure element SE2 is here totally embedded in an integrated circuitcontaining the NFC controller ME and is for example, packed with saidNFC controller in a single package SPCK.

While the secure element SE2 is thus permanently fixed within theapparatus WP, the secure element SE1 (UTCC) is removably lodged withinthe apparatus WP and removably connected to the NFC controller.

The NFC controller is powered by the voltage VPS_main coming from apower management unit PMU connected to a battery. The NFC controller isalso directly connected to the battery.

At last, an antenna ANTI permitting an NFC communication with acontactless device is coupled to the NFC controller.

Information related to two different applications may be thus exchangebetween the secure elements SE1 or SE2 through the NFC controller andthe antenna ANTI.

In both embodiments disclosed in FIGS. 13 and 14, the NFC controller MEmay, in a full power operation mode, either select the secure elementSE1 or the secure element SE2 through the switch SW for performing anSWP communication with selected secure element.

However, in the embodiment disclosed in FIG. 13, in a low power mode(for example, when the battery is off), the secure element SE1 ispowered by the NFC controller ME and SWP communication is only possiblewith this secure element SE1.

As a matter of fact, the secure element SE1 is connected to terminal T20of the switch SW and, in a low power mode, the switch SW is forced bythe pull-down resistor R3 to be in a configuration where terminal Tl isconnected to terminal T20.

As indicated above, the power Vcc of the secure element SE1 is deliveredby the NFC controller.

To be compliant with ETSI TS 102 221, which requires the same powervalue between the main processor and the ETSI TS 102 221 interface ofthe secure element SE1, an additional signal Vref indicating the voltagevalue of the main processor is delivered to the NFC controller.

In the embodiment disclosed in FIG. 14, the secure element SE2 ispowered by the NFC controller ME in low power mode and an SWPcommunication is only possible between the NFC controller and thissecure element SE2 in low power mode.

In this respect, as in a low power mode, switch SW is forced bypull-down resistor R3 into a configuration in which terminal Tl isconnected to terminal T20, the secure element SE2 is connected toterminal 20 while secure element SE1 is connected to terminal T21 of theswitch SW.

FIGS. 15 to 18 illustrate diagrammatically another embodiment of thepresent invention permitting, for example, the user of the wirelessapparatus to choose which auxiliary element will be able to cooperatewith the main element (NFC controller) in the low power mode, i.e. whenthe battery is off.

As for the embodiments illustrated in FIGS. 13 and 14, the device has afirst state in which all the auxiliary elements are able to operate in afirst operation mode, for example in a full power mode.

As it will be explained now more in details the device illustrated inFIG. 15 has a second state in which at least the secure element SE2 isable to operate in a second operation mode, for example in the low powermode.

Thus the device comprises auxiliary selection means at least partlyincorporated in said secure element SE2 and configured, when said deviceis in its second state, to control said SWP link switching for selectingonly one auxiliary element operating in a second operation mode, herethe secure element SE2.

More precisely, the secure element SE2 is powered by Vcc1 provided bythe NFC controller ME.

The contact C1 of the secure element SE1 is connected to the voltage Vccprovided by the main processor in the full power mode, and to thevoltage Vcc1 through a PMOS transistor TRP. The gate of this transistorTRP is connected to Vcc1 through a pull-up resistor R4.

The gate of the transistor TRP is also connected to an input/output portI/O2 of the secure element SE2.

This port I/O2 is also connected to a first input of a EXNOR gate LGT.

The second input of the EXNOR gate LGT is connected to the NFCcontroller for receiving the control signal SWCTRL in the firstoperation mode, and to the pull-down resistor R3 to be forced to thelogical value “0” in the second operation mode.

The output of the EXNOR gate LGT is connected to the control input ofthe switch SW.

Both EXNOR gate LGT and switch SW are powered by Vcc1, which is stillavailable in the second operation mode.

The output terminal T20 of the switch is connected to the contact C6 ofthe secure element SE1, and the input terminal T1 of the switch isswitched to the terminal T20 when the signal present at the controlinput of the switch has the logical value “1”.

The output terminal T21 of the switch is connected to the SWP interfaceof the secure element SE2, and the input terminal T1 of the switch isswitched to the terminal T21 when the signal present at the controlinput of the switch has the logical value “0”.

The secure element comprises also auxiliary processing means PRAconnected to auxiliary memory means MMA, to the port I/O2 and to anotherinput/output port I/O1. The auxiliary processing means may be realizedby logic circuit and/or by software.

The main processor is also configured to receive from a user interfacean indication designating the auxiliary element which is chosen to beable to cooperate with the main element (NFC controller) in the lowpower mode. This indication is processed by the main processor and sentto the NFC controller through the I²C bus, and then to the secureelement SE2 during an SWP transaction in the full power mode. Theauxiliary processing means PRA of the secure element is thus configuredto store in the auxiliary memory means MMA a corresponding configurationindication CFI.

The main processor comprises also detection means configured to detectthe passage from the first state of the device (full power operationmode) to the second state (low power operation mode) and to deliver acorresponding detection signal SDT to the port I/O1. For example, thissignal SDT is representative of the state ON or OFF of the mainprocessor. For example, when the processor is ON, it sets the signal SDTto the logical value “1”, whereas the signal SDT is forced to thelogical value “0” by a pull-down resistor RS when the processor is OFF.

The means PRA, MMA, DTM, TRP, LGT, R4 form here said auxiliary selectionmeans.

The operation of the device in the first state (full power mode) is nowdescribed with reference to FIG. 16.

In this state, all the elements are fully powered by the battery.

The auxiliary control signal CTRLA, provided at the first input of theEXNOR gate LGT, has the logical value “1” due to the pull-up resistorR4.

The transistor TRP is off and the secure element SE1 is powered by theVcc voltage delivered by the main processor.

The NFC controller ME may, in this full power operation mode, eitherselect the secure element SE1 or the secure element SE2 through theswitch SW for performing an SWP communication with selected secureelement.

As a matter of fact, because the signal CTRLA has the logical value “1”the logical value of the control signal SWCTRL delivered by the NFCcontroller will be the logical value of the signal fed at the controlinput of the switch SW.

Further, as explained above, during this full power operation mode, theconfiguration indication CFI may be delivered to secure element SE2 andstored by the auxiliary processing means PRA in the auxiliary memorymeans MMA.

Reference is now made to FIG. 17, to illustrate the case where secureelement SE2 is designated by the configuration indication CFI forcooperating with the NFC controller ME through the SWP link during thelow power mode.

In the low power mode, the secure element SE2 is powered by the voltageVcc1 provided by the NFC controller. As in the embodiments illustratedin FIGS. 13 and 14, the NFC controller is itself powered by theelectromagnetic field received by the antenna ANT1 during an NFCcommunication with a contactless device.

Upon receipt of the detection signal SDT having the logical value “0”,the auxiliary processing means PRA read the configuration indication CFIstored in the auxiliary memory means and delivers the control signalCTRLA having here the logical value “1”.

Further, the control signal SWCTRL is forced to the logical value “0” bythe pull-down resistor R3.

Consequently, the EXNOR gate LGT powered by Vcc1, delivers a logicalvalue “0” to the control input of the switch SW, also powered by Vcc1,allowing the selection of the secure element SE2.

It should be noted here that, in this non-limitative particularembodiment, the transistor TRP is off, and thus the secure element SE1is not powered.

Reference is now made to FIG. 18, to illustrate the case where secureelement SE1 is designated by the configuration indication CFI forcooperating with the NFC controller ME through the SWP link during thelow operation mode.

In the low power mode, the secure element SE2 is powered by the voltageVcc1 provided by the NFC controller.

Upon receipt of the detection signal SDT having the logical value “0”,the auxiliary processing means PRA read the configuration indication CFIstored in the auxiliary memory means and delivers the control signalCTRLA having here the logical value “0”.

Consequently, the transistor TRP is ON, and the secure element SE1 isalso powered by the voltage Vcc1.

Since the control signal SWCTRL is forced to the logical value “0” bythe pull-down resistor R3, the EXNOR gate LGT powered by Vcc1, deliversa logical value “1” to the control input of the switch SW also poweredby Vcc1, allowing the selection of the secure element SE 1.

It should be noted here that the secure element SE1 is powered beforebeing selected by the switch SW due to the delay introduced by the EXNORgate LGT.

The means PRA, MMA, TRP, R4 form also auxiliary power control meansconfigured to control the powering of secure element SE1 and SE2 fromsaid configuration indication.

Of course, as both secure elements SE1, SE2 are powered in the low poweroperation mode, the part LK21 of the SWP link seen by the non-selectedsecure element SE2 is forced in its deactivated state by the pull-downresistor R21.

According to an aspect of the invention, it is thus possible to exchangeinformation between a main element and two auxiliary elements through acontrollable multiplexer/demultiplexer switch without modifying theoperating system of the secure element. Further, only a smallmodification of the operating system of the NFC controller is needed forcontrolling the analog multiplexer/demultiplexer switch SW.

Although different embodiments of the invention have been disclosed withtwo secure elements, other embodiments including more than two secureelements connected to the master SWP interface through amultiplexer/demultiplexer switch SW are also possible.

Further, although the analog switch SW has been located outside the mainelement and the slave elements, it would be possible to integrate theswitch (and eventually the EXNOR gate) within the single package SPCK ordirectly within the main element. In such a case, the outputs of themain element would be for example, the terminals T20 and T21 of theswitch, and terminal Tl of the switch would be connected to theprocessing means of the master interface within said main element.

What is claimed is:
 1. A circuit, comprising: a main processorconfigured to transmit a low-power mode indicator designating anoperation of the circuit in a low-power operating mode; a near fieldcommunication controller (NFC) controller configured to receive thelow-power mode indicator from the main processor; a first universalintegrated circuit card (UICC) coupled to the NFC controller; and asecond UICC coupled to the NFC controller and configured to receive thelow-power mode indicator, the second UICC comprising: an auxiliarymemory configured to store a configuration indicator corresponding tothe low-power operating mode of the circuit; and an auxiliary processorconfigured to retrieve the configuration indicator from the auxiliarymemory in response to receiving the low-power mode indicator from theNFC controller, and to communicate with the NFC controller in thelow-power operating mode.
 2. The circuit of claim 1, further comprisingan antenna coupled to the NFC controller, the antenna configured toexchange an NFC communication with an external contactless device. 3.The circuit of claim 2, wherein the antenna is configured to providepower to the NFC controller by an electromagnetic field received fromthe external contactless device in the low-power operating mode.
 4. Thecircuit of claim 1, wherein the configuration indicator is stored in theauxiliary memory during a full-power operating mode of the circuit. 5.The circuit of claim 1, wherein the second UICC is powered by a voltagefrom the NFC controller in the low-power operating mode.
 6. The circuitof claim 1, wherein the second UICC further comprises an input/outputterminal coupled to the main processor, the main processor configured totransmit a signal to the second UICC to de-activate the second UICC inthe low-power operating mode.
 7. The circuit of claim 6, wherein thefirst UICC is configured to activate, in low-power mode, based on ade-activation signal received by the second UICC from the mainprocessor.
 8. A method, comprising: transmitting, by a main processor ofa circuit, a low-power mode indicator to a near field communication(NFC) controller of the circuit, the low-power mode indicatordesignating an operation of the circuit in a low-power operating mode;receiving, by a universal integrated circuit card (UICC) of the circuit,the low-power mode indicator from the NFC controller; retrieving, by anauxiliary processor of the UICC, a configuration indicator from anauxiliary memory of the UICC, the retrieving in response to receivingthe low-power mode indicator from the NFC controller; and communicating,by the UICC with the NFC controller, in the low-power operating mode. 9.The method of claim 8, further comprising exchanging, by an antenna, anNFC communication between the circuit and an external contactlessdevice.
 10. The method of claim 9, further comprising providing, by theantenna, power to the NFC controller in the low-power operating mode.11. The method of claim 8, further comprising storing the configurationindicator in the auxiliary memory in a full-power operating mode of thecircuit.
 12. The method of claim 8, further comprising providing, by theNFC controller, a voltage to the UICC in the low-power operating mode.13. The method of claim 8, further comprising receiving, by the UICC, asignal from the main processor, the signal de-activating the UICC in thelow-power operating mode.
 14. The method of claim 13, wherein the UICCis a first UICC, the circuit further comprising a second UICC, themethod further comprising activating the second UICC in response to thede-activating the first UICC in the low-power operating mode.
 15. Awireless device, comprising: an antenna configured to exchange a nearfield communication (NFC) with an external contactless device; a mainprocessor configured to transmit a low-power mode indicator designatingan operation of the wireless device in a low-power operating mode; anear field communication controller (NFC) controller configured toreceive the low-power mode indicator from the main processor; auniversal integrated circuit card (UICC) coupled to the NFC controllerand configured to receive the low-power mode indicator, the UICCcomprising: an auxiliary memory configured to store a configurationindicator corresponding to the low-power operating mode of the wirelessdevice; and an auxiliary processor configured to retrieve theconfiguration indicator from the auxiliary memory in response toreceiving the low-power mode indicator from the NFC controller, and tocommunicate with the NFC controller in the low-power operating mode. 16.The wireless device of claim 15, further comprising a second UICCcoupled to the NFC controller and configured to exchange NFCcommunications with the NFC controller.
 17. The wireless device of claim15, further comprising a battery configured to provide power to thewireless device in a full operating mode; and a power management unitcoupled to the battery.
 18. The wireless device of claim 15, furthercomprising a second antenna configured to provide telephonefunctionality to the wireless device.
 19. The wireless device of claim15, wherein the antenna is further configured to provide power to theNFC controller in the low-power operating mode.
 20. The wireless deviceof claim 15, further comprising: a second UICC configured to exchangeNFC communications with the controller; and a switch configured toselectively provide a communication link between each UICC and the NFCcontroller.